Cloud PBX • Onboarding

What to expect when you install a Cloud PBX

A plain-language walkthrough of what actually happens from sign-up to go-live, so a South African business knows exactly what the switch involves before committing.

Last verified 12 June 2026
By the WhichVoIP editorial team
6 min read

No PABX boxHosted in the provider’s cloud

Keep your numberPorted under ICASA portability rules

Days, not weeksTypical go-live for a small team

~100 kbpsBandwidth per call (ITU-T G.711)

The short answer

What actually happens when you install a Cloud PBX?

There is no hardware to install in the traditional sense. The provider sets up your phone system in the cloud, you connect existing computers and handsets or a softphone app, and your numbers are ported across under South Africa’s portability rules. For a small team the whole process usually takes days, with a short window of overlap while your old line is switched off and the new one goes live.

On-premise PABX boxes a Cloud PBX requires

Onboarding stages: plan, provision, port, go-live

Bandwidth per concurrent call (ITU-T G.711)

Things to test before go-live: network, porting, routing

A South African Office Team Setting Up A New Cloud Phone System On Laptops And A Desk Phone — A Cloud PBX install is mostly configuration, not cabling. Most of the work happens in a browser.

What a Cloud PBX install actually involves

If you are picturing engineers running cable and bolting a box to the wall, reset that expectation. A Cloud PBX is a service you configure, not a system you build.

Because the phone system lives in the provider’s data centre, your side of the install is light. There are three practical parts, and none of them needs a server room.

Minimal hardware

Staff can use a softphone app on the computers and mobiles they already own, or affordable IP desk phones where a physical handset is genuinely needed. There is no PABX to buy, house, power or maintain.

Number porting

You keep your existing business numbers. The provider manages the port under South Africa’s number-portability rules; your job is to supply accurate account details and not cancel the old service until the port completes.

Configuration in a browser

Call routing, voicemail, auto-attendants and user extensions are set up in an admin portal. This is where you shape how calls flow, and it is the part worth spending time on before you go live.

✓

Bottom line: the heavy lifting sits with the provider. Your effort goes into porting accurately and configuring call flow, not installing equipment.

The onboarding timeline, stage by stage

Most installs follow the same four stages. Knowing them up front stops the porting window catching you out.

Stage 1 · Plan

Agree your seat count, the numbers to port, and how calls should route. Confirm your internet has headroom for your peak concurrent calls.

Stage 2 · Provision

The provider builds your system in the cloud: users, extensions, voicemail and auto-attendant. You test it on temporary numbers before cutover.

Stage 3 · Port

Your existing numbers move across. There is a short window where the old line is switched off and the new one takes over, so schedule it for a quiet period.

Stage 4 · Go-live & tune

Calls flow on the new system. Spend the first week refining routing, training staff and fixing anything the pilot missed.

What to get right before go-live

A smooth switch comes down to a few checks. Get these right and the rest is routine.

Check the network firstConfirm your connection carries your peak concurrent calls (about 100 kbps each) and prioritise voice traffic on the router if you can.

Port last, not firstKeep your old line active until the new system is built and tested. Never cancel the old service before the port completes.

Pilot with one teamRun a small group on the new system for a few days to shake out routing and call-quality issues before everyone moves.

Train on the featuresA short session on transfers, voicemail and the mobile app turns a new system into one staff actually use.

Set a failover ruleDecide what happens to calls during an outage, such as a mobile-app fallback or a cloud auto-attendant, before you need it.

A Cloud PBX install rarely goes wrong because of the technology. It goes wrong when someone cancels the old line before the new one is ready.

WhichVoIP editorial view

Hands Configuring A Voip Desk Phone Next To A Laptop Showing A Cloud Pbx Admin Dashboard — Most of an install is done in the admin portal: extensions, routing and voicemail, all in a browser.

Cloud PBX onboarding versus an on-prem install

The difference is not subtle. One is a project; the other is a configuration task.

What it takes	On-premise PABX	Cloud PBX
Hardware on site	A PABX box plus cabling	None beyond handsets you choose
Lead time	Weeks, with engineer visits	Days for a small team
Upfront cost	Capital purchase	Monthly per-user seat
Adding a user	Cabling and a site visit	Self-service in the portal
Maintenance	Yours to manage	Handled by the provider

Our verdict

Installing a Cloud PBX is far simpler than the legacy systems it replaces, because most of it happens in software. The two things that decide how smoothly it goes are your internet (it must carry your calls) and your porting discipline (keep the old line until the new one is live). Get those right and a small business can be fully switched over within days, with no server room and no engineer bolting hardware to the wall.

Our recommendation: treat the porting window as the critical path, pilot with one team first, and ask any provider you shortlist to walk you through their onboarding and failover before you sign. If you are moving off an ageing PABX, read our guide on choosing a Cloud PBX after a legacy vendor exit.

Compare Cloud PBX providers for your team

Tell us your seat count and we will match you with South African providers, so you can compare onboarding, porting and pricing side by side.

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Frequently asked questions

How long does it take to install a Cloud PBX?

For a small team, usually days rather than weeks. The system is built in the cloud and tested on temporary numbers, then your existing numbers are ported across during a short cutover window.

Do I need special hardware for a Cloud PBX?

No PABX box is required. Staff can use a softphone app on existing computers and mobiles, with affordable IP desk phones where a physical handset is needed. The system itself lives in the provider’s data centre.

Can I keep my existing phone number?

Yes. Your numbers are ported under South Africa’s number-portability rules. Supply accurate account details and keep the old service active until the port completes, then it switches over.

What internet do I need for a Cloud PBX?

A stable business connection with about 100 kbps of headroom per concurrent call. Most business fibre already has the capacity; prioritising voice traffic on your router helps call quality.

What is the most common mistake when switching to Cloud PBX?

Cancelling the old line before the new system is live and the port has completed. Always port last, keep the old service running in parallel, and pilot with one team before moving everyone.

Keep reading

Choosing a Cloud PBX after a legacy vendor exit
Number porting for VoIP phone systems
The VoIP migration checklist
Cloud PBX phone systems explained

Sources: ICASA number-portability framework (geographic number porting); ITU-T G.711 (voice bandwidth per call); WhichVoIP onboarding guidance. Verified 12 June 2026.